Vibratory separator with automatically adjustable beach

ABSTRACT

A vibratory separator having a basket for supporting screen apparatus for treating material, the basket pivotably mounted on a base, vibratory apparatus connected to the basket for vibrating the basket, the material forming a pool on the screen apparatus, and a beach formed on the screen apparatus, measurement apparatus connected to the basket and positioned above the screen apparatus for measuring a distance from the measurement apparatus to a top surface of the pool, control apparatus for controlling and in communication with the measurement apparatus for receiving signals therefrom indicative of said distance, which distance is indicative of pool depth at that location and which correspond to beach extent, and adjustment apparatus controlled by the control apparatus for adjusting angle of the basket, thereby adjusting extent of the beach.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention is directed to vibratory separators; to apparatuses andmethods for sensing fluid levels in such separators; and to apparatusesand methods for adjusting such levels and for adjusting the extent of abeach area on a screen.

2. Description of Related Art

In many prior art vibratory separators and shale shakers a pool or massof fluid or material is formed on top of one or more screens or screenassemblies which are used to filter material introduced to the separatoror shaker. The depth of this fluid or material can affect efficientoperation of the separator or shaker. Fluid or material that is too deepmay not be adequately filtered. Fluid or material that is too shallowmay flow across a screen too quickly or without sufficient weight to befiltered adequately.

Shale shakers assist in maintaining certain desired properties ofdrilling fluid by using vibrating screens to remove certain largeparticles while allowing certain smaller particles to remain in thefluid. The large undesirable particles may include drilling cuttings anddebris picked up in the drilling process. The smaller particles mayinclude drilling fluid additives that are required for maintainingdesired drilling fluid density and viscosity. The screens on theseshakers have a limited life, and can be expensive and time consuming toreplace. The shaker is turned off and, preferably, rinsed clean prior toscreen replacement.

One factor in screen life is how well the beach area is maintained.“Beach” area is the distance from a fluid-dry interface-with-fluid lineon a final screen to the end of the screen. Thus, a zero beach lengthdescribes a shaker operating with drilling fluid covering the entirescreen area of the final screen and running over to discharge. This canbe costly due to the loss of drilling fluid which flows off, rather thanthrough, a screen. A beach length of 20″ in certain shakers indicates ashaker operating fairly dry, with the last sections of screenpotentially vibrating against completely dry particles. Such dryparticles vibrating on the beach of the last screen can tear holes inthe screen and shorten the screen life. The beach length is affected byvariables such as fluid flow rates and drilling fluid propertiesincluding viscosity, density, temperature, and solids content.

In many prior art separators and shakers tilting or raising mechanismsare provided to adjust the angle of screen(s) with respect to thehorizontal. For example, a prior art shaker S (shown in FIG. 1) has atilting mechanism which permits a screen-containing basket to be tiltedaround a pivot point P up to 5° from the horizontal.

U.S. Pat. No. 4,082,657 discloses a separator apparatus which hasindividual height adjustable mounting structures for each screen unitwhich permit adjustment of the screen unit angle with respect to thehorizontal.

U.S. Pat. No. 6,575,304 B2 discloses an hydraulic ram apparatus beneatha screen body which is used to adjust the angle of incline of the screenbody.

In many prior art systems, a determination of the level of material orfluid on a screen or screen assembly of a separator or shaker is donevisually and then adjustments of screen incline angle or of screensupport incline angle are done manually.

There has long been a need, recognized by the present inventors, toprovide an efficient and accurate measurement of the depth of fluid ormaterial on a screen or screen assembly of a vibratory separator orshale shaker. There has long been a need, recognized by the presentinventors, for such separators and shakers with accurate adjustment ofsuch depth based on measurement thereof. There has long been a need,recognized by the present inventors, for a shale shaker or vibratoryseparator with screen pool depth adjustability to efficiently adjustlast-screen beach extent to enhance screen efficiency and to prolongscreen life.

SUMMARY OF THE PRESENT INVENTION

The present invention, in certain embodiments, teaches a vibratoryseparator (in one particular aspect, a shale shaker) which has sensingapparatus for sensing parameters indicative of the level of fluid ormaterial on a screen or screen assembly supported by the separator and,therefore, for indicating the extent of a beach area on the screen orscreen assembly. In one aspect, a screen or screen assembly itself (or ascreen on holding structure) is able to be inclined to a desired angleto adjust the extent of a beach area adjacent an exit end of a screen. Abeach area is an area adjacent a screen's exit end with two boundarysides—a first side (or rear side) is the side of a pool of material onthe screen (analogous to the seashore) and the second side or front sideis at or near the exit end of the screen. It is important in somesystems to maintain a beach area of desired extent which is sufficientlylarge so that the pool does not extend to or beyond the screen's exitend—which would result in some material not being treated (filtered,separated) by the screen and simply flowing off the end of the screen.It is also important in some systems to insure that the beach area isnot too large which could adversely affect screening efficiency andeffectiveness.

In certain aspects, such a separator also has adjustment apparatus(powered electrically, hydraulically, or pneumatically) for receivinginformation from one or more sensing apparatuses regarding distance tofluid or material at a certain location on a screen or screen assembly(which corresponds to pool depth at the location) and for then adjustingincline angle of the screen or screen assembly to adjust and maintainthe extent of a beach area adjacent an exit end of a screen.

In certain aspects, any suitable basket pivot point is used from abasket center to a basket end. In one particular aspect a basket forsupporting a screen or screen assembly is positioned and configured sothat it pivots at a pivot point relatively near one of its ends; and, inone particular aspect, such a pivot is beneath a rear line which is therear boundary of a desired beach area (“rear” meaning the beach boundaryfurthest away from the exit end of a screen).

The present invention, in certain aspects, discloses a shale shaker orvibratory separator with a screen support or basket for supportingscreen apparatus for treating material introduced into the vibratoryseparator, the basket on a base and pivotable with respect thereto;vibratory apparatus connected to the basket for vibrating the basket;screen apparatus supported by the basket, the material flowing onto thescreen apparatus and forming a pool on the screen apparatus, and a beachon the screen apparatus adjacent the pool; measurement sensor apparatusconnected to the vibratory separator and positioned above the screenapparatus for measuring a distance from the measurement sensor apparatusto a top surface of the pool, the measurement sensor apparatus includinga signal production portion for producing signals indicative of saiddistance and for transmitting said signals; a control system forcontrolling and in communication with the measurement sensor apparatusfor receiving signals from the measurement sensor apparatus indicativeof said distance and for processing said signals to calculate a pooldepth corresponding to said distance, said pool depth related to alocation of an edge of said pool adjacent said beach; and angleadjustment apparatus connected to the basket and controlled by thecontrol system for adjusting angle of the basket, thereby adjustingextent of the beach.

In one particular aspect, a shale shaker according to the presentinvention consists of a vibrating basket which supports multiplescreens. Drilling fluid is directed to flow over the screens from a weirtank. As fluid flows over the screens, drilling fluid and smallerparticles pass through the screens and are returned to the drillingfluid system. The larger particles and pieces remain on top of thescreens, and vibratory action moves them of f an end of the shaker.Within the shaker, the angle at which the basket sits can be changed tomaintain the desired beach area. One or more ultrasonic transducersensor measuring apparatuses mounted above a screen or screens, (in oneaspect above the last screen) measures the fluid level on screen(s) oron the last screen. In one particular aspect a single sensor is usedabove the pool above a last screen which is a pool area that is lessturbulent than previous screen areas and, in one aspect, a basket pivotpoint is located beneath a beach's rear line so that the single sensorprovides all needed information to adjust beach extent as desired. Thelevel of the fluid on the screen(s) is related to the rear or innerbeach boundary. A signal from the sensor(s) indicative ofsensor-to-pool-surface distance is sent to a control system, e.g. acomputerized control system, a programmable logic controlled controlsystem, a digital signal processor and/or a microprocessor based controlsystem which interprets the signal and sends a control signal to aheight adjustment apparatus, e.g., but not limited to, a system with adirectional control valve which controls pressurized hydraulic fluidflow to pistons attached via linkages between the shaker base and basketand/or any basket raising apparatus (mechanical, pneumatic, orhydraulic; e.g. but not limited to hydraulically-powered piston/cylinderapparatuses) of the prior art. In certain aspects, multiple distancemeasurements are made and the controller is programmed to average themeasurements. As the basket is raised or lowered, the basket anglechanges. When the beach width is too long, the height adjustmentapparatus decreases the angle of the basket, and when the beach width istoo short, the angle of the basket is increased. Thus, the desired beachextent is automatically maintained. A desired sensor-to-pool-surfacedistance, and thus a desired beach width can be programmed into thecontrol system for a particular separator, shaker, screen, or screenassembly.

In one particular aspect a power system for providing hydraulic fluidunder pressure to apparatus for raising and lowering a basket usesdouble rod hydraulic cylinders so that dual apparatuses on two sides ofa basket operate in unison. One or more sensors may be connected to orover a basket, to a rear tank, to a skid or base, or to a motor tube ormount. In one aspect a fluid reservoir (hydraulic fluid or gas) and/orfluid pump apparatus is part of a vibratory separator system or part ofa shale shaker. In one particular aspect, a skid, base, or support of ashaker or part of a shaker supports a fluid reservoir; and pumpapparatus on the shaker provides fluid to height adjustment apparatus.

In certain aspects a fluid flow sensor is employed on a vibratoryseparator or shale shaker which gives an indication when the flow ofmaterial ceases so that a basket end near a material input point can belowered so that upon recommencement of the material flow the basketangle is such that material does not flow off a last screen's exit endwithout being treated.

In certain aspects the present invention provides a vibratory separator(e.g. but not limited to a shale shaker) with a basket for supportingscreen apparatus for treating material introduced into the vibratoryseparator, the basket on a base and pivotable with respect thereto;vibratory apparatus connected to the basket for vibrating the basket andthe screen apparatus in the basket; screen apparatus supported by thebasket, the material flowing onto the screen apparatus and forming apool on the screen apparatus, and a beach formed on the screen apparatusadjacent the pool; measurement sensor apparatus connected to thevibratory separator and positioned above the screen apparatus formeasuring a distance from the measurement sensor apparatus to a topsurface of the pool, the measurement sensor apparatus including a signalproduction portion for producing signals indicative of said distance andfor transmitting said signals; a control system for controlling and incommunication with the measurement sensor apparatus for receivingsignals from the measurement sensor apparatus indicative of saiddistance and for processing said signals to calculate a pool depthcorresponding to said distance, said pool depth related to a location ofan edge of said pool adjacent said beach; and angle adjustment apparatusconnected to the basket and controlled by the control system foradjusting angle of the basket, thereby adjusting extent of the beach.

It is, therefore, an object of at least certain preferred embodiments ofthe present invention to provide:

New, useful, unique, efficient, non-obvious vibratory separators andshale shakers and methods of their use;

Such separators and shakers with one or more sensing apparatuses forsensing parameters indicative of the depth of fluid or material onscreen(s) or screen assemblies supported by the separator or shaker,which depth is related to the extent of a beach area on the screen(s) orscreen assemblies;

Such separators or shakers with a screen support which is pivotable ator near one of its ends for screen inclination angle adjustment therebyadjusting beach area;

Such separators or shakers with adjustment apparatus for adjustingscreen inclination angle based on information received from the sensingapparatus or apparatuses;

Such separators or shakers with sensor(s) to sensesensor-to-pool-surface distance on screen(s) and to automatically adjustsaid distance to maintain a desired beach extent on a screen; and, inone aspect, on a last or material-exit screen; and, in one aspect, asingle sensor which, in certain embodiments, is located above a basketpivot point;

Such separators or shakers with material flow sensing apparatus so thatbasket angle can be adjusted and readjusted depending on the materialflow status; and

New, useful, unique, efficient, non-obvious beach adjustment apparatusfor adjusting beach extent on a screen of a vibratory separator or shakeshaker.

The present invention recognizes and addresses the previously-mentionedproblems and long-felt needs and provides a solution to those problemsand a satisfactory meeting of those needs in its various possibleembodiments and equivalents thereof. To one of skill in this art who hasthe benefits of this invention's realizations, teachings, disclosures,and suggestions, other purposes and advantages will be appreciated fromthe following description of preferred embodiments, given for thepurpose of disclosure, when taken in conjunction with the accompanyingdrawings. The detail in these descriptions is not intended to thwartthis patent's object to claim this invention no matter how others maylater disguise it by variations in form or additions of furtherimprovements.

DESCRIPTION OF THE DRAWINGS

A more particular description of embodiments of the invention brieflysummarized above may be had by references to the embodiments which areshown in the drawings which form a part of this specification. Thesedrawings illustrate certain preferred embodiments and are not to be usedto improperly limit the scope of the invention which may have otherequally effective or equivalent embodiments.

FIG. 1 is a schematic side view of a prior art shale shaker.

FIG. 2A is a schematic view of a system according to the presentinvention. FIG. 2B is a schematic side view of shale shaker apparatus ofthe system of FIG. 2A.

FIGS. 3, 4, 5B and 6 are side schematic views of systems according tothe present invention.

FIG. 5A is a schematic view of a prior art shale shaker.

FIG. 7 is a side schematic view of screen assemblies according to thepresent invention.

FIG. 8A is a side schematic view of a screen assembly according to thepresent invention.

FIGS. 8B and 8C are end views of a screen assembly of FIG. 8A.

FIG. 9 is an end view of a system according to the present invention.

FIG. 10A is a side view of a shale shaker according to the presentinvention. FIG. 10B is a side cross-section view of the shaker of FIG.10A. FIG. 10C is a side cross-section view which shows the shaker ofFIG. 10A with its basket tilted. FIG. 10D is a front end view of theshaker of FIG. 10A. FIG. 10E is a schematic diagram of a controlapparatus for the shaker of FIG. 10A. FIG. 10F is a top schematic viewof a vibratory separator according to the present invention.

DESCRIPTION OF EMBODIMENTS PREFERRED AT THE TIME OF FILING FOR THISPATENT

Referring now to FIGS. 2A and 2B, a drilling system 10 according to thepresent invention includes a rotary bit 12 attached to the lower end ofa length of hollow drill pipe 14 suspended from a drilling derrick (notshown).

The drill pipe 14 and attached drill bit 12 are rotated to cut into thesubsurface formation 16 to form a wellbore 18. The drill pipe 14 passesthrough a wellhead assembly 20 located at the surface. The wellheadassembly 20 controls flow of drilling fluid into the well. During thedrilling of the well, a drilling fluid 22 commonly referred to asdrilling mud is pumped down the interior of the hollow drill pipe 14.The drilling mud exits jets such as jet 24 in drill bit 12 and impingesupon a bottom 26 of the well bore 18. The drilling fluid exiting thejets 24 flushes away from the bottom 26 of the wellbore 18 the cuttingsor particles generated as the drill bit 12 cuts into the earthenformation 16. A stream of drilling mud 22 then carries the cuttings andparticles upward through a well annulus 28 (arrows 29) to the wellhead20. The drilling mud 22 with the particles and cuttings carried orsuspended therein, exits the wellhead 20 at outlet 31 and passes througha conduit 30 to a shaker system according to the present invention whichincludes a shale shaker 32.

In the shaker 32, the drilling mud and particles are deposited upon oneor more screens which are vibrated so that the larger particles aresifted out of the drilling mud and carried off the top of the screen(s).

A liquid portion of the drilling mud along with very fine suspendedparticles exits a first shaker outlet 34 and is received in a mud pit36.

Larger particles 44 which are sifted out of the stream of drilling mudexit a second shaker outlet or trough 38 and are conveyed on a conveyoror slide 40 for deposit into a reserve pit 42 or into storage tanks forhaulage to another location. The drilling mud is pumped from the mud pit36 through a line 46 by a mud pump 50. The mud pump 50 then pumps themud through a discharge line 52 which returns it to the interior bore ofdrill pipe 14.

As shown in FIGS. 2A and 2B the shale shaker 32 has a fluid levelsensing apparatus 60 which is in communication with a control apparatus70. The sensing apparatus 60 senses a distance to a top surface of thedrilling mud 22 on a screen 33 of the shaker 32, which is indicative ofmud depth. Via a signal transmission line 62 (or multiple such lines ifneeded) the sensing apparatus sends a signal to the computer apparatus70 indicative of this distance. The apparatus 70 controls the sensingapparatus 60 via a line 63 (or multiple such lines if needed).

The shale shaker 32 (or a screen supporting basket thereof) is supportedby a first support 37 which has a pivotal connection 39 and by a secondsupport 51 which has a pivotal connection 52 and a movable post 53 whichis selectively movable up and down by moving apparatus 54 to pivot theshale shaker 32 (or its basket alone) on the pivotal connection 39 toaffect the angle of the shaker or basket 32, the depth of drilling fluidbeneath the sensing apparatus 60, and the extent of a beach area on thescreen

Via a line 65 the computer apparatus 70 controls a control apparatus 72that selectively operates the moving apparatus 54 (which may bepneumatically, hydraulically or electrically powered as may be any suchapparatus or height adjustment apparatus of any system according to thepresent invention).

The sensing apparatus 60 may be (and as may be the case for any sensorof any system disclosed herein) any suitable known level and/or distancesensing apparatus including, but not limited to, the following types:electrical, optical, electromagnetic, ultrasonic, acoustic, andpulse-echo, and may be like the level sensing systems disclosed in U.S.Pat. Nos. 6,691,025 B2; 5,793,705; 5,319,972; 6,484,088 B1; 6,062,070;and 5,131,271 (all said patents incorporated fully herein for allpurposes) and the systems referenced, referred to or mentioned in thesepatents. The apparatus 70 may be (and as may be for any system disclosedherein) any suitable computer, computers, computer system,microprocessor-based system and/or programmable logic controller(s).

FIG. 3 shows a shale shaker 100 according to the present invention whichhas a basket 101 vibrated by interconnected vibrating apparatus 107. Thebasket 101 supports three screens 102, 103, 104 for treating materialintroduced onto screen 104 from a tank 106.

An ultrasonic level sensor 110 is connected to the basket 101 andselectively senses the distance to, and, therefore the level of thematerial 114 (e.g., drilling fluid with solids entrained therein) at alocation 116 above the screen 103. A control apparatus 111 controls thesensor 110 via a cable 118 and also, via the cable 118, the sensor 110sends signals to the control apparatus 111 indicative of a measurementof the level at the location 116. In one aspect the control apparatus111 includes suitable apparatus (e.g. like the apparatus 70 describedabove) which calculates the depth at the location 116 and, based onsuitable programming in suitable programming media in the controlapparatus 111, adjusts the inclination of the basket 101 usingadjustment apparatus 112 so that the depth at the location 116 ismaintained at a desired level.

In one aspect the basket 101 is pivotally connected to a support 113 ata pivot point 115. The support 113 is secured to a base 105, as is thetank 106 and adjustment apparatus 112. Fluid and/or solid materialflowing through the screens 102-104 flows down into a receptacle 117.Separated material 108 flows off an exit end of the last screen 102.

FIG. 4 shows a shale shaker 120 according to the present inventionsimilar to the shale shaker 100, FIG. 3 (and like numerals indicate likeparts); but the shale shaker 120 has individual tilting mechanisms 131,132, 133 (each with a respective pivot point 131 a, 132 a, 133 a) eachbeneath a respective screen 121, 122, 123. Levels of drilling fluid 128at various locations on the screens 121-123 can be adjusted byselectively changing the inclination of the screens 121-123. Controlapparatuses 134-136 correspond, respectively, to the mechanisms 131-133.A control system 127 with suitable control apparatus (e.g. like theapparatus 70, FIG. 2B) communicates with the control apparatuses 131-133and also with individual level sensors 124, 125, and 126. Each sensor124-126 senses the level of drilling fluid 128 at, respectively,locations 137, 138 and 139. The control apparatus in one aspect ispre-programmed to maintain the drilling fluid levels at locations137-139 at predetermined levels by monitoring the levels with thesensors 124-126 and adjusting the depths at those locations by pivotingthe screens 121-123 by pivoting the individual tilting mechanisms131-133. Any one or any two of the sensors 124-126 may be deleted andthe corresponding tilting mechanism(s) and associated control(s) may bedeleted.

FIG. 5A shows a prior art shale shaker with a pivot point at or near amid-point of a shaker basket (“fine screening basket”). FIG. 5B shows ashale shaker 150 according to the present invention which has a basketpivot point 161 at or near one end of a basket 160. The shaker 150 has aback tank 151 from which material to be treated flows into a scalpingbasket 170 which removes massive and/or gross size pieces and particlesand from which material then flows down onto screens 153-156. Heightadjustment apparatus 158 (controlled as is any adjustment apparatusdisclosed herein) selectively pivots the basket 160 about the point 161.Vibrating apparatus 157 vibrates the basket 160. Material passingthrough the screens flows into a receptacle 159 on a skid 165.

In one aspect the present invention provides a separator like thatdisclosed in U.S. Pat. No. 4,082,657 (incorporated fully herein for allpurposes); but with improvements according to the present invention. Asshown in FIG. 6 a separating device D according to the present inventionfor separating particulate from a fluid stream includes a frame 210having mounted thereon an inlet tank 211 for receiving a fluid to befiltered or cleaned. Screen units 214 a and 214 b are mounted incascaded alignment on the frame 210 by vibration mount means generallydesignated as 215 a and 215 b which each includes a vibrating means 216mounted therewith for vibrating screen units 214 a and 214 bsimultaneously.

The frame 210 includes first and second side members 210 a (only one isillustrated) which are connected together by a front end connecting rod210 b and a rear connecting rod 210 c. The front and rear connectingrods 210 b and 210 c cooperate with the side members such as 210 a toprovide a generally rectangular form having an opening therethroughthrough which the cleaned fluid stream may pass to a recovery areapositioned therebelow. The side frame members such as 210 a may beI-beams or other suitable frame members for supporting the structure tobe disclosed here.

The inlet tank 211 has connected therewith an inlet line 211 b forreceiving the fluids to be cleaned. In one aspect the screen unit 214 aand 214 b includes a metal frame with screening material thereon.

The screen units are releasably mounted in screen unit mounting assemblysupports 222 and 222 a.

Each screen unit is supported by four adjustable posts 235 (two shown oneach side of each screen; e.g. as described in U.S. Pat. No. 4,082,657).Optionally, interposed between the screen units' supports 222, 222 a arespring mechanisms 233 and 234. Vibratory apparatuses 216 vibrate thescreen units.

A sensor 240 on a support 240 a senses the depth of fluid on the screenunit 214 a and a sensor 242 on a support 242 a senses the depth of fluidon the screen unit 214 b. A control apparatus 250 (like any disclosedherein) is in signal communication with the sensors 240, 242 via cables243, 244. The control apparatus 250 is also in communication via cables247, 248 with control apparatuses 245, 246 which control theheight-adjustable posts 235. The control apparatuses 250, 245, 246 maybe like any control apparatus and/or computer apparatus described above.

FIG. 7 shows three screen assemblies 261, 262, 263 according to thepresent invention which may be used in any system according to thepresent invention in which screen assemblies, screens, or individualscreen supports are tilted or moved to adjust fluid depth at a locationon a screen assembly or screen. Each screen assembly 261-263 has anexpandable member 264 (e.g., but not limited to, an expandable bellowsor seal) which insures that sealing contact is maintained betweenadjacent screen assemblies (or between a screen assembly end and amember on a basket against which a screen assembly end abuts). In oneaspect as shown the expandable members 264 are bellows seals; but it iswithin the scope of this invention for any suitable seal or sealingmaterial to be used which can expand and contract sufficiently tomaintain a seal between adjacent screens.

FIGS. 8A-8C illustrate a screen assembly 265 according to the presentinvention which has a flexible end seal 266 which seals against an endof an adjacent screen 267. The seal 266 is sufficiently wide that itwill seal against the end of the screen assembly 267 when theinclination of the screen assembly 267 is changed (and/or when theinclination of the screen assembly 265 is changed (e.g. in response to asignal from a fluid level sensor above either or both screen assemblies265, 267. Optionally, the screen assembly 267 may also have an end seal264.

FIG. 9 shows a vibratory separator 270 according to the presentinvention with walls 274 and a screen assembly 271 in a crownedconfiguration with fluid 272 to be treated thereon. A fluid level sensor273 connected to a wall 274 of the separator 270 with a connector 275senses fluid level near a center point of the screen assembly 271 (asviewed in FIG. 9). A fluid level sensor 276 senses fluid level near thewall 274. It is within the scope of the present invention to locatefluid one or more sensors at any point above a screen assembly in avibratory separator or shaker. Optionally, either sensor 273 or 276 maybe deleted.

FIGS. 10A-10D show a shale shaker 300 according to the present inventionwhich is like a KING COBRA Shale Shaker commercially available fromVarco International, Inc., but which has improvements according to thepresent invention. The shale shaker 300 has a skid or base 302 on whichis a basket 306 which is vibrated by vibration apparatus 304. From aweir tank 308 fluid, e.g. drilling fluid with drilled cuttings anddebris therein, flows onto a first screen 310 which is supported by ascreen support 310 a connected to the basket 306. Part of the fluid thenflows onto a second screen 311 supported by a screen support 311 aconnected to the basket 306 and then part of the fluid flows onto a lastscreen 312 supported by a screen support 312 a connected to the basket306. Part of the fluid flows off an exit end 312 b of the screen 312onto an optional lower screen 313 which is supported by a screen support313 a connected to the basket 306.

The fluid forms a pool 315 above the screens 310-312. Depending on thefluid, on the fluid viscosity, on the fluid's solids content, on therate of fluid flow, and the through-put of the screens, a beach 316 iscreated at the exit end 312 b of the screen 312. It is desirable tooptimize the extent of this beach 316 and, in certain aspects, it ispreferred that the beach, as viewed in FIG. 10B, be sufficiently largethat no fluid flows untreated off the last screen 312.

An ultrasonic transducer sensor measurement apparatus 320 a is connectedto the basket 306 (e.g. to a motor tube 309 and/or such a sensorapparatus 320 b is connected to a weir tank 308) and is, optionally,positioned above the pool 315, e.g. over an entry end 310 b of thescreen 310 or over an entry end 312 c of the screen 312. Such locationsfor the apparatus 320 provide measurement at locations providing thegreatest range of pool depth and therefore, the greatest range foradjusting beach extent; i.e., such a location insures that theapparatuses 320 a and/or 320 b will have a sensor-to-pool-surfacedistance to measure since in most cases there will be fluid at somedepth at this point beneath the apparatus or apparatuses 320. Theapparatuses 320 a and/or 320 b are in communication with a controlapparatus 330. The sensor apparatuses generates a signal indicative ofsensor-to-pool distance which indicates depth of the pool 315 beneaththe sensor apparatus(es). Optionally, either the sensor 320 a or thesensor 320 b is deleted.

The control apparatus 330 selectively controls a control valve 336 whichallows hydraulic fluid under pressure from a reservoir 338 pumped by anhydraulic pump 337 to move to and from two hydraulic cylinderapparatuses (one shown, FIG. 10A) which are on opposite sides of theshaker 300. A flow control valve 332 controls the flow of fluid into/outof the pistons and adjusts the rate of stroke in the cylinderapparatuses 333, 334 and a flow control valve 335 limits the flow offluid to/from the pistons and adjusts the rate of stroke out of thecylinder apparatuses 333, 334. An hydraulic cylinder apparatus 350 hasan extendable piston 351 pivotably connected to a pivot plate 353 at apivot point 365. The plate 353 is pivotably connected at a pivot point357 to the basket 306. A housing 350 of the apparatus 334 is secured toa mount 359 which is pivotably connected to the basket 306. A link 355is pivotably connected to the plate 353 at a pivot point 366 and thelink 355 is connected to a link 356 that is pivotably connected at apivot point 354 to a basket support 340. The basket support 340 issupported by the hydraulic cylinder apparatuses and by bases 341. Shafts367 of the basket supports 340 are pivotably mounted on the bases 341. Ascale 339 indicates the angle of the support 340 with respect tohorizontal (i.e. assuming the skid or base 302 is level). The support340 is connected to springs 346, 343 which support basket mounts 345 and342, respectively; and similar springs and mounts are on the other sideof the basket.

In another aspect the plate 365 is deleted and the hydraulic cylinderapparatuses are oriented almost vertically and the hydraulic cylinderapparatuses' pistons 351 are pivotally connected to the basket support340 for selectively raising and lowering it to adjust beach extent.

FIG. 10C shows the basket 306 tilted as compared to the basket 306 asshown in FIG. 10A.

In one aspect a vibratory separator or shale shaker according to thepresent invention may employ a material flow sensor which produces asignal indicative of the presence or absence of material flowing ontoscreen apparatus; e.g., but not limited to, drilling fluid with drilledsolids flowing onto screen apparatus of a shale shaker. Such anindication is valuable in insuring that, upon flow commencing againfollowing cessation of material flow which is common when drilling isstopped, a screen or a basket is not inclined at such an angle that arelatively low depth pool is formed resulting in the loss of untreateddrilling fluid flowing off a screen exit end. By adjusting screen orbasket angle so that flow recommencement is accommodated, a pool isformed of sufficient depth and extent that all or the great majority ofmaterial is treated and an optional amount of drilling fluid flowsthrough the screen and is recovered.

Optionally, a shaker 300 as shown in FIGS. 10A and 10B (with or withouta sensor or sensors like the sensor 320 a and/or 320 b) has a materialflow switch device 307 connected to vibratory separator adjacent amaterial input tank like the tank 308 for sensing when material isflowing. The device 307 may be any suitable known flow sensor apparatus,including, but not limited to paddle switch systems, including, but notlimited to, FS-550 SERIES paddle switches from Gems Sensors Co.

The device 307 is in communication with and controlled by the controller330 and, in one aspect, signals from the device 307 override signalsfrom sensors like the sensors 320 a and 320 b so that the controller 330knows that material flow has ceased (rather than an indication from thesensors 320 a, 320 b that the pool is very shallow). In response tosignals from the device 307 the controller 330 can activate theapparatus for adjusting basket angle.

Once material flow into the basket is again proceeding, the controller330 (acting upon signals from the sensor 320 a and/or the sensor 320 b)adjusts the basket angle to maintain the desired beach extent. Althoughone particular flow sensor has been mentioned, it is to be understoodthat any suitable known flow sensor device or system may be used,including, but not limited to, ultrasonic transducer systems.

The controller 330 may be any suitable known commercially availablecontroller apparatus, including, but not limited to computerizedsystems, digital signal processor systems, programmable logic controllersystems, and/or microprocessor systems. One suitable sensor apparatusand associated control system is the model XPS-10 and HYDRO RANGER 200from Siemens.

FIG. 10F shows schematically a vibratory separator or shake shaker 400according to the present invention which has a screen-supporting basket402 with pivot members 414 pivotally mounted on supports 404 on a skidor base 406. Adjustment apparatuses 408, 410 on either side of thebasket 402 (like any adjustment apparatus described herein) raise andlower an end 412 of the basket 402, pivoting it about the pivot members414. In one aspect a rear line 416 of a beach area 420 of a screen 430supported in the basket 402 coincides with a line between the pivotmembers 414.

A sensor 418 (like any sensor disclosed herein, including but notlimited to those in FIGS. 1-10A) is positioned above a fluid entry endof the screen 430 on a connecting member 422 connected to the basket402. A sensor 451 (like any sensor herein) is positioned above a fluidentry end of the screen 434 and may be conveniently connected to a baror beam which is connected to the tank 452 and/or to the basket 402.Material flows from a screen 432 to the screen 430 and from a screen 434to the screen 432. Any suitable tank 452 and/or fluid introductionapparatus may be used. Vibrating apparatus 440 vibrates the basket 402.

A power apparatus 441 connected to the shaker 400 powers the adjustmentapparatuses 408, 410 and may be located at any suitable location on theshaker 400 including, but not limited to, on the basket 402 or on theskid 406. Optionally the power apparatus 441 is any such apparatus orsystem disclosed herein. In one aspect the power apparatus 441 includesan hydraulic pump in fluid communication with an hydraulic fluidreservoir 440 via a line 444 and the apparatuses 408, 410 arehydraulically-powered apparatus in fluid communication with the pump vialines 442, 443. Control apparatus 450 (as any disclosed herein) controlsthe apparatus 441, the sensor 418, a sensor 460, a controller 456,and/or the sensor 451. Optionally, a material flow sensor 460 connectedto the tank 452 (or at any suitable location in the separator 400) whichis like the sensor 307, FIG. 10A, senses the presence or absence ofmaterial flowing from the tank 452 onto the screen 434. The sensor 460is in communication with the control apparatus 450 and, in response tosignals from the sensor 460, the control apparatus 450 adjusts thebasket angle to accommodate material flow and to adjust forrecommencement of flow following flow cessation. Optionally, a flow ratecontroller 456 controls the amount of fluid introduced onto the screen434 from the weir tank 452 and a control switch 455 of the controller456 is in communication with the control apparatus 450.

It is within the scope of this invention for the apparatuses 408, 410 tobe located at any desirable effective location with respect to thebasket, as may be the case with any adjustment apparatus disclosedherein.

The present invention, therefore, in some and not necessarily allembodiments, provides a vibratory separator having a screen support orbasket for supporting screen apparatus for treating material introducedinto the vibratory separator, the basket on a base and pivotable withrespect thereto, vibratory apparatus connected to the basket forvibrating the basket, screen apparatus supported by the basket, thematerial forming a pool on the screen apparatus, and a beach on thescreen apparatus adjacent the pool, measurement sensor apparatusconnected to the vibratory separator and positioned above the screenapparatus for measuring a distance from the measurement sensor apparatusto a top surface of the pool, the measurement sensor apparatus includinga signal production portion for producing signals indicative of saiddistance and for transmitting said signals, a control system forcontrolling and in communication with the measurement sensor apparatusfor receiving signals from the measurement sensor apparatus indicativeof said distance and for processing said signals to calculate a pooldepth corresponding to said distance, and angle adjustment apparatusconnected to the basket and controlled by the control system foradjusting angle of the basket, thereby adjusting extent of the beach.Such a vibratory separator may have one or some, in any possiblecombination, of the following: wherein the vibratory separator is ashale shaker and the material is drilling fluid with drilled cuttingstherein; wherein the screen apparatus includes at least an exit screenwith an exit end from which material separated by the screen apparatusflows off the screen apparatus for discharge from the vibratoryseparator, wherein the basket is at an angle such that the beach isformed adjacent an edge of the pool adjacent said exit end, and whereinthe control system controls extent of the beach; wherein the controlsystem controls extent of the beach to maintain the beach on the exitscreen; wherein the screen apparatus is a plurality of screens placedadjacent each other in the basket, each screen with an associated screensupport connected to the basket; wherein the angle adjustment apparatusincludes a basket support pivotably mounted to the base and movingapparatus for selectively moving the basket up and down; wherein thebasket has a fluid entry end and a fluid exit end and wherein the basketis pivotably mounted adjacent the fluid exit end, and wherein the angleadjustment apparatus moves the basket's fluid entry end; wherein themoving apparatus includes hydraulic cylinder apparatus for moving thebasket; wherein the hydraulic cylinder apparatus includes twohydraulically powered piston apparatuses, each on a side of the basketfor moving the basket; wherein each hydraulically powered pistonapparatus is pivotably interconnected with corresponding linkageapparatus, the linkage apparatus pivotably connected to the basketsupport adjacent the fluid entry end of the basket; wherein themeasurement sensor apparatus is ultrasonic apparatus; wherein theultrasonic apparatus is at least one ultrasonic apparatus; wherein themeasurement sensor apparatus is a plurality of distance sensorapparatuses; wherein the plurality of sensor apparatuses includes afirst ultrasonic sensor apparatus spaced-apart from a second ultrasonicsensor apparatus, the first ultrasonic sensor apparatus above one sideof the screen apparatus and the second ultrasonic sensor apparatus abovean opposite side of the screen apparatus; wherein the measurement sensorapparatus is from the group consisting of electrical, optical,electromagnetic, ultrasonic, acoustic, and pulse-echo apparatus; whereina rear boundary of the beach is along a rear beach line and the basketis pivotably connected to the base beneath the rear beach line; and/orwherein the angle adjustment apparatus is powered by power apparatusfrom the group consisting of pneumatic power apparatuses, hydraulicpower apparatuses and electric power apparatuses.

In conclusion, therefore, it is seen that the present invention and theembodiments disclosed herein and those covered by the appended claimsare well adapted to carry out the objectives and obtain the ends setforth. Certain changes can be made in the subject matter withoutdeparting from the spirit and the scope of this invention. It isrealized that changes are possible within the scope of this inventionand it is further intended that each element or step recited in any ofthe following claims is to be understood as referring to all equivalentelements or steps. The following claims are intended to cover theinvention as broadly as legally possible in whatever form it may beutilized. The invention claimed herein is new and novel in accordancewith 35 U.S.C. § 102 and satisfies the conditions for patentability in §102. The invention claimed herein is not obvious in accordance with 35U.S.C. § 103 and satisfies the conditions for patentability in § 103.This specification and the claims that follow are in accordance with allof the requirements of 35 U.S.C. § 112.

1. A vibratory separator comprising a basket for supporting screenapparatus for treating material introduced into the vibratory separator,the basket on a base and pivotable with respect thereto, vibratoryapparatus connected to the basket for vibrating the basket, screenapparatus supported by the basket, the screen apparatus having an exitend, the material flowable onto the screen apparatus to form a pool onthe screen apparatus and a beach on the screen apparatus adjacent thepool, material not passing through the screen apparatus flowing off anexit end of the screen apparatus, the beach adjacent the exit end of thescreen apparatus, the beach having a rear boundary line on the screenapparatus and a front boundary at or near the exit end of the screenapparatus, measurement sensor apparatus connected to the vibratoryseparator and positioned above the screen apparatus for measuring adistance from the measurement sensor apparatus to a top surface of thepool, the measurement sensor apparatus including a signal productionportion for producing signals indicative of said distance and fortransmitting said signals, a control system controlling and incommunication with the measurement sensor apparatus for receivingsignals from the measurement sensor apparatus indicative of saiddistance and for processing said signals to calculate a pool depthcorresponding to said distance, said pool depth related to a location ofan edge of said pool adjacent said beach, angle adjustment apparatusconnected to the basket and controlled by the control system foradjusting angle of the basket, thereby adjusting extent of the beach,the basket pivotably connected by two spaced-apart pivot members to thebase beneath said rear boundary line, the basket pivotable at a pivotpoint beneath the rear boundary line, and a control system controllingthe angle adjustment apparatus to maintain the rear boundary line abovea line between the two spaced-apart pivot members and thereby maintain adesired beach extent.
 2. The vibratory separator of claim 1 wherein thevibratory separator is a shale shaker and the material is drilling fluidwith drilled cuttings therein.
 3. The vibratory separator of claim 1 apool on the screen apparatus, the control system for controlling extentof the beach so that the pool does not extend beyond the exit end of thescreen apparatus.
 4. The vibratory separator of claim 1 wherein thescreen apparatus comprises a plurality of screens placed adjacent eachother in the basket, each screen with an associated screen supportconnected to the basket.
 5. The vibratory separator of claim 1 whereinthe angle adjustment apparatus includes a basket support pivotablymounted to the base and moving apparatus for selectively moving thebasket up and down.
 6. The vibratory separator of claim 5 wherein thebasket has a fluid entry end and a fluid exit end and wherein the basketis pivotably mounted adjacent the fluid exit end, and wherein the angleadjustment apparatus moves the basket's fluid entry end.
 7. Thevibratory separator of claim 6 wherein the moving apparatus includeshydraulic cylinder apparatus for moving the basket.
 8. The vibratoryseparator of claim 7 wherein the hydraulic cylinder apparatus includestwo hydraulically powered piston apparatuses, each on a side of thebasket for moving the basket.
 9. The vibratory separator of claim 8wherein each hydraulically powered piston apparatus is pivotablyinterconnected with corresponding linkage apparatus, the linkageapparatus pivotably connected to the basket support adjacent the fluidentry end of the basket.
 10. The vibratory separator of claim 1 whereinthe measurement sensor apparatus is ultrasonic apparatus.
 11. Thevibratory separator of claim 10 wherein the ultrasonic apparatus is atleast one ultrasonic apparatus.
 12. The vibratory separator of claim 1wherein the measurement sensor apparatus comprises a plurality ofdistance sensor apparatuses.
 13. The vibratory separator of claim 12wherein said plurality includes a first ultrasonic sensor apparatusspaced-apart from a second ultrasonic sensor apparatus, the firstultrasonic sensor apparatus above one side of the screen apparatus andthe second ultrasonic sensor apparatus above an opposite side of thescreen apparatus.
 14. The vibratory separator of claim 1 wherein themeasurement sensor apparatus is from the group consisting of electrical,optical, electromagnetic, ultrasonic, acoustic, and pulse-echoapparatus.
 15. The vibratory separator of claim 1 wherein the angleadjustment apparatus is powered by power apparatus from the groupconsisting of pneumatic power apparatuses, hydraulic power apparatusesand electric power apparatuses.
 16. The vibratory separator of claim 1further comprising flow sensor apparatus connected to the vibratoryseparator for sensing the flow of the material onto the screenapparatus, the flow sensor apparatus controlled by and in communicationwith the control system, the control system adjusting basket angle inresponse to signals from the flow sensor apparatus.
 17. A vibratoryseparator comprising a basket for supporting screen apparatus fortreating material introduced into the vibratory separator, the basket ona base and pivotable with respect thereto, vibratory apparatus connectedto the basket for vibrating the basket, screen apparatus supported bythe basket, the material flowable onto the screen apparatus to form apool on the screen apparatus, a beach formable on the screen apparatusadjacent the pool, measurement sensor apparatus connected to thevibratory separator and positioned above the screen apparatus formeasuring a distance from the measurement sensor apparatus to a topsurface of the pool, the measurement sensor apparatus including a signalproduction portion for producing signals indicative of said distance andfor transmitting said signals, a control system controlling and incommunication with the measurement sensor apparatus for receivingsignals from the measurement sensor apparatus indicative of saiddistance and for processing said signals to calculate a pool depthcorresponding to said distance, angle adjustment apparatus connected tothe basket and controlled by the control system for adjusting angle ofthe basket, thereby adjusting extent of the beach, the angle adjustmentapparatus including a basket support pivotably mounted to the base andmoving apparatus for selectively moving the basket up and down, thebeach having a rear boundary line and the basket pivotably connected tothe base beneath said rear boundary line, the control system controllingextent of the beach such that the rear boundary line is maintained in aposition above the pivotal connection, and the basket at an angle suchthat the beach is formed adjacent an edge of the pool adjacent an exitend of the screen apparatus.
 18. A method for treating materialintroduced to a vibratory separator, the method comprising introducingmaterial to a vibratory separator, the vibratory separator comprising abasket for supporting screen apparatus for treating material introducedinto the vibratory separator, the basket on a base and pivotable withrespect thereto, vibratory apparatus connected to the basket forvibrating the basket, screen apparatus supported by the basket, thescreen apparatus having an exit end, the material flowable onto thescreen apparatus to form a pool on the screen apparatus and a beach onthe screen apparatus adjacent the pool, material not passing through thescreen apparatus flowing off an exit end of the screen apparatus, thebeach adjacent the exit end of the screen apparatus, the beach having arear boundary line on the screen apparatus and a front boundary at ornear the exit end of the screen apparatus, measurement sensor apparatusconnected to the vibratory separator and positioned above the screenapparatus for measuring a distance from the measurement sensor apparatusto a top surface of the pool, the measurement sensor apparatus includinga signal production portion for producing signals indicative of saiddistance and for transmitting said signals, a control system controllingand in communication with the measurement sensor apparatus for receivingsignals from the measurement sensor apparatus indicative of saiddistance and for processing said signals to calculate a pool depthcorresponding to said distance, said pool depth related to a location ofan edge of said pool adjacent said beach, angle adjustment apparatusconnected to the basket and controlled by the control system foradjusting angle of the basket, thereby adjusting extent of the beach,the basket pivotably connected by two spaced-apart pivot members to thebase beneath said rear boundary line, the basket pivotable at a pivotpoint beneath the rear boundary line, and the control system controllingthe angle adjustment apparatus to maintain the rear boundary line abovea line between the two spaced-apart pivot members and thereby maintain adesired beach extent, forming a pool of the material on the screenapparatus so that there is a beach on the screen apparatus, treating thematerial in the vibratory separator, adjusting the angle of the basketand the extent of the beach with the angle adjustment apparatus, andmaintaining extent of the beach with the control system.
 19. The methodof claim 18 wherein the vibratory separator is a shale shaker and thematerial is drilling fluid with drilled cuttings therein.
 20. The methodof claim 18 wherein the vibratory separator has flow sensor apparatusconnected to the vibratory separator for sensing the flow of thematerial onto the screen apparatus, the flow sensor apparatus controlledby and in communication with the control system, the control systemadjusting basket angle in response to signals from the flow sensorapparatus, the method further comprising adjusting the basket angle withthe angle adjustment apparatus upon cessation of material flowing intothe basket to accommodate the recommencement of material flowing intothe basket onto the screen apparatus.